Bandit shows progress indicator even when passing --quiet

[fniessink]

Describe the bug
Bandit shows a progress indicator when the number of files is greater than 50, even though the --quiet flag is passed

To Reproduce
Steps to reproduce the behavior:
Run "bandit --quiet src" on a folder with more than 50 files.

Expected behavior
Bandit should not show a progress indicator when --quiet is passed

Bandit version

bandit 1.6.2
  python version = 3.8.0 (v3.8.0:fa919fdf25, Oct 14 2019, 10:23:27) [Clang 6.0 (clang-600.0.57)]

Additional context
I'd be happy to submit a PR.

[oriash93]

I believe this is the cause of the issue:

bandit/bandit/core/manager.py

Lines 223 to 225 in b78c938

	# display progress, if number of files warrants it
	if len(self.files_list) > self.progress:
	sys.stderr.write("%s [" % len(self.files_list))

While passing the --quiet flag just sets the logging level to WARN:

bandit/bandit/cli/main.py

Lines 415 to 416 in c6b1302

	if args.quiet:
	_init_logger(log_level=logging.WARN)

@fniessink let me know if you haven't started yet, I'd like to take up on that.

[fniessink]

I can prepare a PR. What's the preferred solution: using the logger to display the progress (instead of stderr) in the run_tests method?

[oriash93]

I am not a maintainer so it's not up to me to decide. I would use the logger.